Typically, a tile installer begins by going to the customer's job site and measuring the surface to be tiled to produce a cost estimate. Often, the customer and installer can only discus the tile layout in general terms. The measuring is typically done with a tape measure and the measurements are recorded. The installer returns to the office to process the measurements to produce the cost estimate and calls the customer. If the customer accepts the offer, the installer returns to the job site with an assistant and lays out the grid lines with chalk lines and tape measure. Finally, the installer begins laying tiles. Tiles are cut and fitted one-by-one as necessary. Often, intersections do not align. Often many slivers and small tiles result. These are unsightly and are likely to loosen.
The whole procedure is inefficient from beginning to end. The measurement is inexact and the computations are error prone. There is little selection in the tile pattern and the installed pattern is typically not the optimum in cost, durability and aesthetics.